Cyrtopogon sp. - specimen "B"

Soooo.... bear with me a little bit, but this is kind of exciting. Last week I posted up a photo of one of these robber flies. I don't know much at all about them so I went to BugGuide for an ID. I was figuring that "w" mark on the back would make it easy. Little did I know... what came back to me from the experts over there was that there is a good possibility that this species is un-described - but I only had that one photo, which wasn't really enough to start to really make that determination.

So - we decided to go back and see if we could catch one. I can't say I was really expecting to be successful.... turns out they are certainly not locally scarce - we saw a number of them and I captured two. They are now up on BugGuide, with more views for the experts to look over and I will be able to take/send them away to an expert as well.

In these photos the flies are still alive... I'm a little paranoid about losing them or damaging them, so forgive the plastic cup background...

What a fantastic project, @morpheme. I am really rooting for you. It would be such an awesome award and recognition if you'd get this species described, no matter how long the road may be. It will also be very interesting to follow and learn about the process of getting a species described. Best of luck, and thank you kindly for posting it on JD.Posted 3 months ago

What I've always done (and learned when I was back in school) is to take a separate image of a ruler with the same lens/camera set up. Then you know your magnification and can put a discrete scale bar on your photos if they are published. We even had tiny little micrometer rulers mounted on microscope slides for photomicroscopy. Posted 3 months ago, modified 3 months ago

Sorry for my ignorance, but how is it better to photograph the ruler separately? How does camera/lens matter if the ruler and subject are in the same scene? I feel like I'm overlooking something.Posted 3 months ago

Maybe it's a hold over from film days? But we'd always photograph a ruler on a separate negative. You get a nice clean and flat image of the ruler without trying to wrangle both your ruler and your subject into focus at the same time (which can be next to impossible - especially if your subject can move), you can use one ruler for your entire shoot (as long as you don't alter your focal length) and you don't have the distraction of a ruler in the frame.
The one thing to note is that I don't use the focusing ring on the lens for each shot in a case such as this - that would slightly change the magnification. The lens is set and left at it's maximum extension and all focusing is done by moving the camera.
In the old days you'd make a print of the ruler at the same time you were printing your images and use that to measure out your scale bar (or do the math) - these days you can put the ruler in a layer in Photoshop.
Here's someone doing this in their lab. http://www.photomacrography.net/forum/viewtopic.php?t=4030Posted 3 months ago

Ah - and the journey comes a a quick end ;P . With the updated photos over at BugGuide the little ladies have been ID'd as C. longimanus. The professor over there says that the samples he has from further south do not have as distinctive a W marking on them as the Washington specimens, but he's ID them from other characteristics. I must say it was fun though - and a learning experience for sure. Posted 3 months ago

Hi Morpheme,
Ahw ... bummer indeed ;o) But good to have gone through the exercise and an interesting result with the regional variation in colour pattern nevertheless. Who knows - it may result in a subspecies or something at some point :o) Could still be interesting to send the samples in to an expert - always good to have such variants in a collection for later examination and also a good thing that these now show on BugGuide under the correct name. So all's well that ends well, I suppose :o)
Cheers, ArpPosted 3 months ago

Cyrtopogon longimanus Loew, 1874 is a Robberfly (Asilidae) known from North America. It is closely related to C. marginalis, also known from the eastern U.S. and Canada, sharing a puffed-up, shiny black scutellum, which lines-up with a series of shiny-black spots along the sides of the thorax with that species.